NPR SWH33003-4 Piston Ring Set Honda K24 2.4L 87mm Standard Bore 4-Cylinder

The NPR SWH33003-4 is a complete four-cylinder piston ring set engineered by Nippon Piston Ring Co., Ltd. (NPR) for Honda and Acura K24-series 2.4L DOHC engines. This set covers all four pistons in a standard bore 87mm configuration, making it the ideal solution for engine rebuilds, overhauls, or ring replacements requiring OEM-grade quality.

Key Features:

• Complete 4-Cylinder Set: Includes rings for all four pistons — no need to purchase per-cylinder
• Standard 87mm Bore: Designed for stock bore applications on K24-series engines
• 3-Ring Design per Cylinder: 1st compression ring (1.2mm), 2nd compression ring (1.0mm), and oil control ring (2.0mm)
• OEM-Grade Construction: Manufactured by Nippon Piston Ring Co., Ltd., a Tier 1 OEM supplier with decades of precision engine component manufacturing
• Premium Surface Treatments: Features barrel-face (BF-IB) compression rings with gas nitriding (GN) surface treatment for superior wear resistance and sealing
• Drop-In Fitment: Direct replacement for Honda OEM part numbers 13011-R40-A12 and 13011-5A2-A11

Ring Specifications:

• Bore Diameter: 87.0mm
• 1st Compression Ring: 1.2mm height, 2.65mm radial width — BF-IB shape, Gas Nitrided
• 2nd Compression Ring: 1.0mm height, 2.5mm radial width — Taper-face (TUC) shape, Steel
• Oil Control Ring: 2.0mm height, 2.45mm radial width — NIFF-H type, Gas Nitrided

NPR piston rings are trusted by engine builders and OEM manufacturers alike for their consistent quality, tight tolerances, and long service life. The SWH33003-4 is the go-to ring set for K24 engine rebuilds demanding factory-level performance and durability.

OEM Cross-Reference Part Numbers: 13011-R40-A12, 13011-5A2-A11